Regasolic soil and soil formation processes

There is NO dominant soil forming process in Regosols. These are soils at the very beginning of soil formation, and whatever soil forming processes do occur in them, they are just starting. Consequently, there is no B horizon in them and even if A or O or LFH horizons are present they are very thin; while C horizon is often labeled just as 'C' or with that modifier 'j' (eg Cgj).
Accumulation of clay or Na+ can be considered as examples of translocation soil forming processes, as long at they came to that horizon from another horizon.

Ok thank you! If accumulation of certain things don't come from a different horizon, would that instead be considered an example of addition soil forming processes?

Yes, that is correct